when i start up minecraft launcher i will press start it downloads something and then shows a crash report that says 

Unable to save download
Name: ig_ng.json
URL: https://resources.download.minecraft.net/54/5448d2b4717775a7e50996224a4cac1f1f0af374
Error details: The process cannot access the file because it is being used by another process.

Attempting to move successful download.
Filename on disk: 26b9-216f-333a-413f
Path: C:\Users\15406\AppData\Local\Temp\26b9-216f-333a-413f
Exists: File

and ive tried a lot to fix it